Study Links Maternal Antibodies to Autism

According to today's Science Daily, "New research from the UC Davis M.I.N.D. Institute and Center for Children's Environmental Health has found that antibodies in the blood of mothers of children with autism bind to fetal brain cells, potentially interrupting healthy brain development." The article goes on to say:

The study authors also found that the reaction was most common in mothers of children with the regressive form of autism, which occurs when a period of typical development is followed by loss of social and/or language skills. The findings raise the possibility that the transfer of maternal antibodies during pregnancy is a risk factor for autism and, at some point, that a prenatal test and treatment could prevent the disorder for some children.

How significant is this finding? It's important to put it into context. The study compared blood samples from 123 mothers -- 61 whose children have autism and 62 whose children are typically developing. They discovered an unusual reacitivity pattern in just seven of the 61 samples from the autism group. The important points are these: none of the samples in the non-autistic group had this reactivity pattern - and six of the seven positive samples were from mothers of children with regressive autism.

In short, these findings are very preliminary. They cannot lead to definitive conclusions, though some are likely to point the study as "proving" a connective between the immune system and autism. On the other hand, they are suggestive of such a link, and will provide a starting place for further investigation. According to Dr. van Der Water, the researcher who led this study, "IgG antibodies are responsible for long-term immune system responses to infection, but they can also contribute to autoimmune diseases such as arthritis, multiple sclerosis and lupus. IgG also crosses the placenta in order to provide key immune system protectants to a growing fetus and newborn child."

The next step in this research will be to "conduct the same study with women who are pregnant and already have a child with autism, because such women are much more likely to have another child with the disorder."

"If women in this next phase of the study give birth to a child eventually diagnosed with autism, blood analyses from all stages of her pregnancy will give us a clear picture of the immune system factors that were in play during gestation and could have altered her child's neurodevelopment," Van de Water said.

Other key next steps are to identify the specific proteins targeted by autism-specific maternal antibodies and their role in neurodevelopment and to determine whether or not exposure to maternal IgG during pregnancy leads to behavioral or social distinctions in offspring. Animal model studies are now under way to help answer these questions.